The invention relates to a device for blocking a vehicle, comprising a guide track which can be disposed along a driveway, a carriage which engages on the guide track and is displaceable therealong in guided manner and which is provided with transversely protruding wheel engaging means and locking means for locking the carriage.
Such a device is known from Netherlands patent application 9302280. The wheel engaging means are herein displaceable in transverse direction relative to the carriage.
A device of the present type is used particularly at loading platforms, where a truck with its loading opening at the rear can be manoeuvred against a loading opening or platform of a storage area. The device herein prevents the truck being able to roll away, which is particularly dangerous when for instance cargo is being transported into and/or out of the truck with fork-lift trucks.
The known device is quite complicated. It comprises separate drive means for the carriage and the wheel engaging means.
The invention therefore has for its object to provide a vehicle blocking device of the type stated in the preamble which is of simple construction.
This objective is achieved with the device according to the invention according to the following. During the rearward movement of the carriage along the guide track the front end of the carriage rises upward in the movement along the rising front end of the guide track. One of the elements of the wheel engaging means on the front end of the carriage herein also rises upward and can thus move against the front side of a wheel of the vehicle for blocking in order to block this vehicle at the desired position. The device can take a particularly simple form since no separate drive means are necessary for the carriage and the wheel engaging means. With a suitable embodiment of the wheel engaging means the carriage can be carried along in rearward direction by the wheel of the truck for blocking and, after blocking of the carriage relative to the guide track, the wheel is blocked.
A favorable embodiment is characterized in that the rear end of the carriage hereby engages in the part of the guide track extending substantially parallel to the driveway so that this rear end, in the movement rearward from the front end, can run smoothly.
A very simple and robust construction is hereby possible with the present invention. A particularly suitable C-profile is a profile which is already applied for vehicle lifts. A carriage is here also movable in the profile using wheels which are enclosed in the C-profile.
The carriage can be automatically co-displaced by wheels of different diameter rearward from the position at the front end of the guide track, wherein the front end of the carriage rises upward and the transverse protrusion arranged on the front end of the carriage can fulfil the blocking function of the wheel. In order to obtain a wide adaptability to wheel diameters the embodiment of FIG. 5 is preferably applied.
A noted objective of the present invention is that the spring force advantageously remains practically constant over the long stroke of the second transverse protrusion.
For blocking of the wheel it is necessary that the first transverse protrusion comes to lie on the front side of the wheel. This can be brought about in simple manner according to the present invention. The wheel can readily travel smoothly over the transverse protrusion.
A suitable embodiment of locking means of the device according to the invention provides that carriage can be locked herewith in any random position relative to the guide track.
A good guiding of the rod relative to the holder is achieved by applying the measure wherein the rod has a circular periphery and is provided with at least one longitudinal groove, the holder has a corresponding circular opening with at least one inward protruding ridge which falls into the corresponding longitudinal groove in an unlocked position and in which the complementary grooves are arranged, and wherein the blocking means can rotate the rod on its longitudinal axis from the unlocked position into a locked position.
The rod can be manufactured simply from a commercially available threaded rod. Only the longitudinal groove or grooves have to be arranged in the rod.